One of the major expenses associated with operation of a backhoe machine is the costly replacement of the digging teeth located on the digging bucket thereof. Replacement of the digging teeth also requires shutdown of the machine and a considerable amount of a technician's time is involved in removing the old teeth and substituting new teeth therefor.
During heat treating of the cast metal, the manufacturer of digging teeth must compromise between the hardness of the cutting edge and the brittleness of the tooth body, because a highly brittle metal will break when engaging hard rock and the like. Therefore, a tooth made sufficiently hard to cut rock will often break and for this reason a compromise in ductility must be made while carrying out heat treatment of the teeth.
Accordingly, it is desirable to be able to make the cutting edge of a digging tooth associated with excavating machines such as backhoe buckets, for example, of very hard material while the rest of the tooth is made of ductile material. It is desirable that the hard cutting edge be removably affixed to the relatively ductile main body of the digging tooth in such a manner that only the marginal leading end which forms a cutting edge need be replaced from time to time in order to restore the digging tooth.